The invention relates to a filter for fluids, especially fuels, having a body supporting a filter fabric and which serves to keep opposed sides of the filter body formed by the filter fabric spaced a distance from one another and having a pump connection neck positioned on the exterior of the filter body. The interior of the filter body has an inlet opening. The supporting body is completely enclosed by the filter fabric and has a connection to the exterior via the inlet opening and a pump connection neck. The filter has a first part containing the pump connection neck and at least one second part positioned in an angle with respect to the first part.
A filter of this kind is shown in PCT Publication No. WO 00/03784. In this known filter, the first part and the second part together form the filter body, wherein the two parts are connected to one another by the means of a joint. The second part and the first part (together with the filter fabric) can be folded from a straight starting position into an angular position, and by the means of a locking device can be fixed in the angular position. Filters of this kind should have a construction as simple as possible. Fuel filters are intended to be mounted in the fuel tank of vehicles. The filter function here is performed by the filter fabric, wherein the supporting body is serving to keep the opposed sides of the filter body formed by the filter fabric at a distance from one another since otherwise both sides could partly stick together, whereby the filter area presented would be decreased. The above described filter makes it possible to have a largest possible filter area in a smallest possible space, wherein especially in connection with fuel filters the known filter can be positioned in an extremely small suction space such that a complete emptying of the fuel from the fuel container is possible. By the construction according to which the two parts are extending in an angle, especially in a right angle to each other, the filter demands an extremely small space in spite of a large filter area.
Starting out from the known filter of the above defined kind, it is the task to be solved by the present invention to drastically simplify the design and construction of the filter while maintaining all advantages such that the production costs of the filter, too, can be drastically decreased.
This task is solved in a filter of the above defined kind basically by the features that the first part is formed by a tubular body which on its first end has the pump connection neck extending generally in a right angle with respect to the main axis of the tubular body and which, on it second end, is provided with an axially extending inlet opening. The second part of the filter is formed of a filter body comprised of a supporting body and the filter fabric. The filter body is fixedly connected in a predetermined angular position with respect to the tubular body.
In a first aspect the invention is a vehicle fuel filter for mounting to a fuel pump in a fuel tank comprising a tubular body having an axis, a first end and a second end opposite the first end; a pump connection neck positioned on the first end of the tubular body and having a filter outlet opening for mounting the filter on a fuel pump intake, the filter outlet opening having an axis at a substantially right angle to the axis of the tubular body; an inlet opening on the second end of the tubular body, the inlet opening extending axially in the direction of the axis of the tubular body; an envelope of filter fabric surrounding the inlet opening such that fuel entering into the envelope can pass into the tubular body through the inlet opening; and a supporting body fixedly connected to the tubular body at the second end and at a predetermined angle to the tubular body, at least a portion of the supporting body preventing the filter envelope from collapsing.
The preferred filter of the invention has a two-part construction formed from the first part as a simple tubular body, which is fixedly connected with the actual filter body (which forms the second part of the filter) in a chosen angular position corresponding to the demands of the use, instead of a comparatively complicated joint section. The simple tubular body enables an almost complete emptying of the fuel tank because the filter also includes an intake opening opposite to the pump connection neck, with filter fabric fixed therein. With this additional intake opening, the suction distance of the filter is decreased to almost one quarter, whereby, for example, an engine in the starting phase can start-up more quickly. Further, this additional intake opening has the advantage that the fuel tank can be emptied down to the level of said intake opening.
In a preferred embodiment according to the invention, the intake opening has at least the cross-section of the pump connection neck. The flow from the intake opening to the pump is improved by this feature.
In spite of the fact that, according to the field of use, many deliberate shapes of the cross-section are possible, according to an embodiment of the invention it is further preferred that the tubular body has an rectangular cross-section. This has the advantage of a simple construction of the pump connection neck and of a flat filter area in the intake opening.
It is further preferred that the supporting body is injection molded onto the filter fabric forming one side of the filter body. This simplifies the production of the filter.
It is further preferred that the filter fabric forming the other side of the filter body be connected with the filter fabric forming the one side of the filter body by a weld forming part or all of the circumference of the filter body. This further simplifies the method of production.
An especially preferred embodiment of the invention uses a tubular body that has a reinforcement at the inlet opening. The reinforcement surrounds the inlet opening and forms an interior shoulder. The connection piece of the filter abuts the interior shoulder in such a way that the free cross-section for the flow in the inlet opening remains unchanged.
It is preferred that the connection piece be permanently fixed on the inlet opening of the tubular body by ultrasonic welding or the like.
To further simplify the production, the outer interior edge of the inlet opening preferably has an inlet bevel.
A further especially preferred embodiment of the invention includes a clamping device next to the pump connection neck on the exterior of the tubular body for mounting the filter on the suction side of a pump.
This clamping device preferably has a unitary lateral projection of the tubular body and is formed by a slot surrounded by a downwardly extending skirt, wherein the skirt has a slight conicity. The conicity preferably is about 3xc2x0.
This preferred embodiment of the clamping device has the advantage that the mounting of the filter on the suction side of a pump is substantially simplified compared with the prior art because the tubular body and projection are made of suitable artificial resin. The resilient properties of the conically designed skirt are sufficient to safely fix the filter on the pump connector on the suction side of the pump by simply sliding the slot over a plug or the like provided on the pump. In prior art constructions it was necessary to form a pocket into which a metal clip was inserted, which had to be secured against falling out by an additional step.